What is NISP and MNI?
- Number of Individual Specimens - counts each bone and fragment as one unit
- Minimum Number of Individual - tends to underestimate the actual number under medium fragmentation
What are the basics for Forensic Science? (3)
- identification - identification of a chemical compound using libraries and reference materials
- classification - to assign an exhibit of evidence to a group of like objects based on descriptors
- individualization - linking a piece of evidence to a single source e.g. suspect, evidence
What are the scientific method? (5)
- observation - measures or describes something about the physical world
- hypothesis - a tentative explanation for an observation or a scientific problem that can be tested by further investigation
- experiment - a procedure that attempts to measure observable predictions to test a theory or a law
- law - a statement that summarizes past observations and predicts future ones; always holds true
- theory - a proposed explanation for observations and laws; true until proven otherwise
The Frye Rule
- the evidence produced by scientific analysis is admissible as long as the techniques are accepted as valid by the relevant scientific community
- from lie detector or polygraph
Rule 702
If scientific, technical or other specialized knowledge will assist the trier of fact to understand the evidence or determine a fact in issue, a witness qualified as an expert by knowledge, experience, training, or education, may testify thereto in the form of an opinion or otherwise.
Daubert Decision
Judges serve as “gate keepers” for evidence
Daubert hearings determine the merit of evidence
What are the three stages of time around death?
Antemortem – occurring prior to the death of the individual
Perimortem – occurring at/around the time of death
Postmortem – occurring after the time of death
What are the possible postmortem changes?
- Decomposition – the state or process of rotting or decay
- Mummification – drying of soft tissues due to exposure to hot or cold, dry environments unfavorable to bacterial growth
- Saponification – the conversion of fatty tissues of the body to a soapy, way substance
- Alteration and scattering by scavengers
- Movement and modification by running water
Taphonomy
- The study of what happens after an organism is dead and until the discovery of its remains
- Interpretation of primarily outdoor death scenes and postmortem processes
Forensic Archaeology?
Recovery of scattered or buried remains
Facial Reconstruction / Approximation?
Extrapolation of soft tissue form based on skeletal form
What is Forensic Anthropology?
Forensic Taphonomy
Forensic Archaeology
Facial Reconstruction / Approximation
Biomechanical injuries
What are the task for a Anthropologist?
- Identify the victim or make a biological profile
- Reconstructing the postmortem period
- Provide data regarding the death event
What are the characteristics to be identified?
Estimated Stature; Sex; Congenital anomaly – something unusual or different at birth; Medical condition; Population
What is sexual dimorphism and what are the differences?
The systematic difference in form between individuals of different sex in the same species
e.g. Stature, hip width, jaw line, brow ridge, size of joint surface, thinner cartilage
What kind of injuries are there?
• Blunt force trauma – usually the result of
assault, abuse, accidents or resuscitative
efforts
• Sharp force trauma – caused by sharp
objects, including knives, axes, etc.
• Equifinality – a given result can be caused by
many paths
What are the certainties?
- Possible – consistent with circumstances
- Presumptive or Preponderance of the evidence – more likely than not
- Positive – all evidence supports conclusions
How to calculate t-factor?
- Find your degrees of freedom in the df column (total measurements - two).
- Find the value of the t-factor in the column underneath the desired certainty (e.g., 90%). If your t-factor is larger than this number, then there is a greater than a 95% possibility that the difference between the two values is not due solely to chance and that there is a statistical basis for concluding that the two measurements are not the same.
Thin Layer Chromatography stages?
◦ Spotting
◦ Development
◦ Visualization
Other chromatography?
High-performance liquid chromatography; gas chromatography (destructive), headspace analysis
CSI models
- Traditional
- Crime Scene Technicians
- Major Crime Squad
- Lab Crime Scene Scientist
- Collaborative Team
Crime scene documentation
Notification Information Arrival Information Scene Description Victim Description Crime Scene Team Video Recording Photographing Sketching Digital Imaging
Crime scene search models
link method line/strip method grid method zone method wheel or ray method spiral method
What is chain of custody
document showing how a sample is treated and by whom
